Phenotypic and genotypic detection of resistance mechanisms in carbapenem-resistant gram-negative bacteria isolated from Egyptian ICU patients with first emergence of NDM-1 producing Klebsiella oxytoca. - Related Documents




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212301.0000Phenotypic and genotypic detection of resistance mechanisms in carbapenem-resistant gram-negative bacteria isolated from Egyptian ICU patients with first emergence of NDM-1 producing Klebsiella oxytoca. BACKGROUND AND OBJECTIVES: Carbapenems are considered the last resort to treat several infections, particularly in intensive care units (ICUs). However, increasing carbapenem resistance is problematic because it leads to high morbidity and mortality rates. This study aimed to determine the rate of carbapenem resistance among Gram-negative bacteria collected from patients in ICUs and to identify their resistance mechanisms using phenotypic and genotypic methods. MATERIALS AND METHODS: Antimicrobial susceptibility testing was carried out using the disc diffusion method among 180 Gram-negative bacterial isolates. Productions of carbapenemases, metallo-beta-lactamases (MBLs) and the harboring of carbapenemase-encoding genes, were detected in 40 selected carbapenem-resistant Gram-negative bacteria (CR-GNB). RESULTS: Of 40 selected CR-GNB isolates, 28 (70%), and 20 (50%) isolates were phenotypically positive for carbapenemase, and MBL production, respectively. Furthermore, 22 (55%) showed amplification of one or more of the carbapenemase-encoding genes, including bla (NDM-1), bla (VIM-2), and bla (OXA-48). This study described the first emergence of NDM-1 producing Klebsiella oxytoca in Egyptian ICUs. CONCLUSION: High incidence of CR-GNB detected in the ICUs in our study area may be attributed to the overuse of antibiotics, including carbapenems, and improper application of infection control measures. These findings confirm the need for the application of a strict antibiotic stewardship program.202236721446
212410.9999Evaluation of Phenotypic and Genotypic Characteristics of Carbapnemases-producing Enterobacteriaceae and Its Prevalence in a Referral Hospital in Tehran City. BACKGROUND & OBJECTIVE: Carbapenem-resistant Enterobacteriaceae is a growing concern worldwide including Iran. The emergence of this pathogen is worrying as carbapenem is one of the 'last-line' antibiotics for treatment of infections caused by multi drug resistant gram- negative bacteria. The main objective of this study was to determine the prevalence of carbapenem-resistant Enterobacteriaceae in a referral hospital in Tehran, Iran. METHODS: In this study, all positive isolates of Enterobacteriaceae recorded in blood, urine, and other body fluids were studied during April 2017 to April 2018 in a referral hospital in Tehran. All cases of resistance to carbapenems were first tested by modified Hodge test. All cases with positive or negative test, after gene extraction, were examined genotypically based on the primers designed for the three Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), and OXA-48 genes by conventional PCR method. RESULTS: 108 isolates (13.6%) were resistant to all cephalosporins as well as to imipenem and meropenem. In a genotypic study, including 45 isolates, 13 isolates were positive for OXA-48 gene, 11 isolates for OXA-48 and NDM genes, 11 isolates for OXA-48, NDM and KPC genes, 4 isolates for OXA-48 genes and KPC, 3 isolates for NDM, one isolate for KPC. On the other hand, two isolates were negative for all three genes examined. CONCLUSION: OXA-48 gene was one of the most common genes resistant to carbapenems in Iran. According to studies, the prevalence of antibiotic resistance in Iran is rising dramatically, which reduces the choice of antibiotics to treat severe infections in the future.202032215024
93020.9999Isolation of Carbapenem and Colistin Resistant Gram-Negative Bacteria Colonizing Immunocompromised SARS-CoV-2 Patients Admitted to Some Libyan Hospitals. The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a devastating effect, globally. We describe, for the first time, the occurrence of carbapenem-resistant bacteria colonizing SARS-CoV-2 patients who developed hospital-associated infections with carbapenemase-producing, Gram-negative bacteria at some isolation centers of SARS-CoV-2 in the eastern part of Libya. In total, at first, 109 samples were collected from 43 patients, with the samples being recovered from oral (n = 35), nasal (n = 45), and rectal (n = 29) cavities. Strain identification was performed via matrix assisted laser desorption ionization-time of flight (MALDI-TOF). Antibiotic susceptibility testing was carried out on Mueller-Hinton agar, using the standard disk diffusion method. MIC determination was confirmed via E-TEST and microdilution standard methods. A molecular study was carried out to characterize the carbapenem and colistin resistance in Gram-negative bacterial strains. All of the positive results were confirmed via sequencing. Klebsiella pneumoniae (n = 32), Citrobacter freundii (n = 21), Escherichia coli (n = 7), and Acinetobacter baumannii (n = 21) were the predominant isolated bacteria. Gram-negative isolates were multidrug-resistant and carried different carbapenem resistance-associated genes, including NDM-1 (56/119; 47.05%), OXA-48 (15/119; 12.60%), OXA-23 (19/119; 15.96%), VIM (10/119; 8.40%), and the colistin resistance mobile gene mcr-1 (4/119; 3.36%). The overuse of antimicrobials, particularly carbapenem antibiotics, during the SARS-CoV-2 pandemic has led to the emergence of multidrug-resistant bacteria, mainly K. pneumoniae, A. baumannii, and colistin-resistant E. coli strains. Increased surveillance as well as the rational use of carbapenem antibiotics and, recently, colistin are required to reduce the propagation of multidrug-resistant strains and to optimally maintain the efficacy of these antibiotics. IMPORTANCE In this work, we describe, for the first time, the occurrence of carbapenem-resistant bacteria colonizing COVID-19 patients who developed hospital-associated infections with carbapenemase-producing, Gram-negative bacteria at some isolation centers of COVID-19 in the eastern part of Libya. Our results confirmed that the overuse of antimicrobials, such as carbapenem antibiotics, during the COVID-19 pandemic has led to the emergence of multidrug-resistant bacteria, mainly K. pneumoniae and A. baumannii, as well as colistin resistance.202337042782
212630.9999Carbapenemase genes among multidrug resistant gram negative clinical isolates from a tertiary hospital in Mwanza, Tanzania. The burden of antimicrobial resistance (AMR) is rapidly growing across antibiotic classes, with increased detection of isolates resistant to carbapenems. Data on the prevalence of carbapenem resistance in developing countries is limited; therefore, in this study, we determined the prevalence of carbapenemase genes among multidrug resistant gram negative bacteria (MDR-GNB) isolated from clinical specimens in a tertiary hospital in Mwanza, Tanzania. A total of 227 MDR-GNB isolates were analyzed for carbapenem resistance genes. For each isolate, five different PCR assays were performed, allowing for the detection of the major carbapenemase genes, including those encoding the VIM-, IMP-, and NDM-type metallo-beta-lactamases, the class A KPC-type carbapenemases, and the class D OXA-48 enzyme. Of 227 isolates, 80 (35%) were positive for one or more carbapenemase gene. IMP-types were the most predominant gene followed by VIM, in 49 (21.59%) and 28 (12%) isolates, respectively. Carbapenemase genes were most detected in K. pneumoniae 24 (11%), followed by P. aeruginosa 23 (10%), and E. coli with 19 isolates (8%). We have demonstrated for the first time a high prevalence of MDR-GNB clinical isolates having carbapenem resistance genes in Tanzania. We recommend routine testing for carbapenem resistance among the MDR-GNB particularly in systemic infections.201424707481
99840.9999Extended spectrum beta-lactamases among Gram-negative bacteria of nosocomial origin from an intensive care unit of a tertiary health facility in Tanzania. BACKGROUND: Resistance to third generation cephalosporins due to acquisition and expression of extended spectrum beta-lactamase (ESBL) enzymes among Gram-negative bacteria is on the increase. Presence of ESBL producing organisms has been reported to significantly affect the course and outcome of an infection. Therefore infections due to ESBL isolates continue to pose a challenge to infection management worldwide. The aim of this study was to determine the existence and to describe phenotypic and genotypic characteristics of ESBLs in an Intensive Care Unit (ICU) setting in Tanzania. METHODS: Between October 2002 and April 2003, clinical information and samples were collected from patients suspected to have nosocomial infections in an Intensive Care Unit of a tertiary hospital in Tanzania. The isolates were identified, tested for antimicrobial susceptibility and analysed for presence of ESBL genes. RESULTS: Thirty-nine Gram-negative bacteria were isolated from clinical samples of 39 patients. These isolates included 13 Escherichia coli, 12 Enterobacter spp, 5 Pseudomonas spp, 4 Proteus spp, 2 Klebsiella. pneumoniae, 2 Citrobacter freundii and 1 Chryseomonas luteola. Eleven (28.2%) of these isolates were ESBL producing. The ESBL genes characterised were SHV-12, SHV-28 and CTX-M-15. The ESBL producing isolates were more resistant to gentamicin and ciprofloxacin than non-ESBL producing isolates. CONCLUSION: This study shows the presence of ESBL genes among Gram-negative bacteria in the ICU setting in Tanzania. There is a need to institute strict hospital infection control policy and a regular surveillance of resistance to antimicrobial agents.200516225701
212550.9999Emergence of Carbapenem-Resistant Gram-Negative Isolates in Hospital Settings in Djibouti. Introduction: The antimicrobial resistance (AMR) of bacteria is increasing rapidly against all classes of antibiotics, with the increasing detection of carbapenem-resistant isolates. However, while growing prevalence has been reported around the world, data on the prevalence of carbapenem resistance in developing countries are fairly limited. In this study, we investigated and determined the resistance rate to carbapenems among multidrug-resistant Gram-negative bacteria (MDR-GNB) isolated in Djibouti and characterized their resistance mechanisms. Results: Of the 256 isolates, 235 (91.8%) were identified as Gram-negative bacteria (GNB). Of these GNBs, 225 (95.7%) isolates exhibited a multidrug resistance phenotype, and 20 (8.5%) isolates were resistant to carbapenems, including 13 Escherichia coli, 4 Acinetobacter baumannii, 2 Klebsiella pneumoniae and 1 Proteus mirabilis. The most predominant GNB in this hospital setting were E. coli and K. pneumoniae species. Carbapenemase genes such as bla(OXA-48) and bla(NDM-5) were identified, respectively, in six and four E. coli isolates, whereas the carbapenemase bla(NDM-1) was identified in three E. coli, two K. pneumoniae, one P. mirabilis and one A. baumannii. Moreover, three A. baumannii isolates co-hosted bla(OXA-23) and bla(NDM-1). Materials and Methods: A total of 256 clinical strains collected between 2019 and 2020 were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). Antibiotic susceptibility testing was performed using disk diffusion and E-test methods. Real-time polymerase chain reaction (RT-PCR), standard PCR and sequencing were used to investigate genes encoding for extended-spectrum-β-lactamases, carbapenemases and colistin resistance genes. Conclusions: We report, for the first time, the presence of MDR-GNB clinical isolates and the emergence of carbapenem-resistant isolates in Djibouti. In addition to performing antimicrobial susceptibility testing, we recommend phenotypic and molecular screening to track the spread of carbapenemase genes among clinical GNB isolates.202337508230
212760.9999Molecular characterization of carbapenem-resistant Klebsiella pneumoniae in a tertiary university hospital in Turkey. The aim of this study was to identify the resistance genes and genetic relationship of carbapenemase-resistant Klebsiella pneumoniae (CRKP) identified in a tertiary university hospital in Turkey. During the study, CRKP was isolated from 137 patients. Resistance genes were studied in 94 isolates. Among these isolates, most of the CRKP produced only oxacillinase (OXA)-48 (91.5%); however, 4.3% of the isolates produced only New Delhi metallo-beta-lactamase 1 (NDM-1), 1% produced both OXA-48 and NDM-1, and 3.2% produced imipenem. This study adds Turkey to the growing list of countries with NDM-1-producing bacteria and shows that NDM-1 may easily spread worldwide.201323623803
91870.9999Carbapenem Resistance in Gram-Negative Bacteria: A Hospital-Based Study in Egypt. Background and Objectives: The global spread of carbapenem resistance and the resulting increase in mortality forced the World Health Organization (WHO) to claim carbapenem-resistant enterobacteriaceae (CRE) as global priority pathogens. Our study aimed to determine the prevalence of carbapenemase-encoding genes and major plasmid incompatibility groups among Gram-negative hospital-based isolates in Egypt. Material and Methods: This cross-sectional study was carried out at Mansoura University Hospitals over 12 months, from January to December 2019. All the isolates were tested for carbapenem resistance. The selected isolates were screened by conventional polymerase chain reaction (PCR) for the presence of carbapenemase genes, namely bla(KPC), bla(IMP), bla(VIM), and bla(NDM-1). PCR-based plasmid replicon typing was performed using the commercial PBRT kit. Results: Out of 150 isolates, only 30 (20.0%) demonstrated carbapenem resistance. Klebsiella pneumoniae was the most resistant of all isolated bacteria, and bla(NDM) was the predominant carbapenemases gene, while the most prevalent plasmid replicons were the F replicon combination (FIA, FIB, and FII) and A/C. Plasmids were detected only in Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae, and Pseudomonas aeruginosa. Remarkably, we found a statistically significant association between carbapenemase genes and plasmid replicons, including bla(NDM), IncA/C, and IncX. Conclusions: Our study demonstrated an alarming rise of plasmid-mediated carbapenem-resistant bacteria in our locality. The coexistence of resistance genes and plasmids highlights the importance of a targeted antibiotic surveillance program and the development of alternative therapeutic options at the local and international levels. Based on our results, we suggest a large-scale study with more Enterobacteriaceae isolates, testing other carbapenemase-encoding genes, and comparing the replicon typing method with other plasmid detection methods. We also recommend a national action plan to control the irrational use of antibiotics in Egypt.202336837486
211980.9999Detection of bla(IMP) and bla(VIM) metallo-β-lactamases genes among Pseudomonas aeruginosa strains. Acquired Metallo-β-Lactamases (MBLs) are emerging resistance determinants in Pseudomonas aeruginosa and other gram-negative bacteria.Using Combination Disk Diffusion test, it was found that among 83 imipenem non-susceptible P. aeruginosa strains, 48 (57.9%) were MBL producers. PCR and Sequencing methods proved that these isolates were positive for blaIMP-1 genes, whereas none were positive for bla(VIM) genes. The mortality rate due to MBL-producing Pseudomonas infection was 4 (8.3%) among the hospitalized patients. Therefore, identification of drug resistance patterns in P. aeruginosa and detection of MBLs producing isolates are of great importance in the prevention and control of infections.201323638331
93190.9999Epidemiological characteristics and antimicrobial susceptibility among carbapenem-resistant non-fermenting bacteria in Brazil. INTRODUCTION: Non-fermenting Gram-negative bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii are widespread in the environment and are increasingly associated with nosocomial infections. Extensive and indiscriminate use of antibiotics in hospitals has contributed to an increased number of infections caused by these microorganisms, that are resistant to a wide variety of antimicrobials, including β-lactams. This study aimed to isolate and identify carbapenem-resistant Acinetobacter spp. and P. aeruginosa from hospitalized patients, to determine their antimicrobial susceptibility patterns and to screen for blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, and blaOXA-143 genes among the isolated bacteria. METHODOLOGY: Antimicrobial resistance patterns were performed using the disk-diffusion method. Genetic markers related to carbapenem resistance were screened by polymerase chain reaction. RESULTS: Carbapenem-resistant Acinetobacter spp. (n = 44) and P. aeruginosa (n = 28) samples were isolated from patients admitted to a tertiary hospital. Polymyxin B was the only effective drug for all isolates. Considering the oxacillinase gene screening, genetic markers were observed only in Acinetobacter isolates. The most frequent genotype observed was blaOXA-23+/blaOXA-51+ (45.5%), followed by blaOXA-51+/blaOXA-143+ (41%). The oxacillinase genes blaOXA-24 and blaOXA-58 were not detected. High mortality rates (> 70%) were observed. CONCLUSIONS: The data suggest the need for rational use of antimicrobials associated with early diagnosis of multidrug-resistant bacteria, especially considering non-fermenting Gram-negative rods, which are widespread in hospitals. The findings of blaoxa-51(-) strains suggest the occurrence and spread of non-A. baumannii species throughout our hospitals. Effective implementation of surveillance programs in hospitals is needed to reduce infectious and resistant intra- and inter-species bacteria.201627367001
2121100.9999Investigation of VIM, IMP, NDM-1, KPC AND OXA-48 enzymes in Enterobacteriaceae strains. Gram-negative bacteria especially Enterobacteriaceae species have become an increasing etiologic agent of nosocomial infections. The development of resistance to carbapenems have become an increasing problem in the treatment of nosocomial infections. Especially carbapenamases are common for Enterobacteriaceae strains. This study was performed to detect the types of carbapenemases in Enterobacteriaceae strains isolated from various clinical samples. Enterobacteriaceae species were isolated from urine, blood, tracheal aspirates, wound, and other respiratory samples. Susceptibility of isolates to imipenem, meropenem and ertapenem was tested. Carbapenemase genes were studied using HyplexSuperBug ID kit. VIM (1-13), IMP (1-22), NDM-1, KPC(1-10) and OXA-48 genes were investigated. Ninety-five isolates of Enterobacteriaceae spp. were included in the study. Sixty isolates were resistant to imipenem, meropenem and ertapenem and 20 isolates were found resistant to imipenem or ertapenem while 15 were susceptible to all carbapenems. Among the isolates with carbapenem resistance, 57 were positive for one carbapenemase gene and susceptible isolates did not have carbapenemase gene. OXA-48 was found in 49 of the isolates (86%), NDM-1 in 6 (10.5%) isolates, VIM in 2 isolates. IMP and KPC gene loci were not identified. Carbapenemase genes play a crucial role in the development and spread of resistant strains.201526051720
934110.9999High Carbapenem Resistance Caused by VIM and NDM Enzymes and OprD Alteration in Nonfermenter Bacteria Isolated from a Libyan Hospital. Acinetobacter baumannii and Pseudomonas aeruginosa are among the most prevalent pathogens causing a wide range of serious infections in hospitalized patients and contaminating intensive care units and inanimate surfaces. The purpose of this study was to investigate the mechanism of carbapenem resistance in clinical and hospital environmental isolates of A. baumannii and P. aeruginosa recovered from a Libyan hospital. From a total of 82 Gram-negative bacteria, 8 isolates of A. baumannii and 3 isolates of P. aeruginosa exhibited resistance to imipenem with minimum inhibitory concentrations ranging from 16 to >32 μg/mL. Five isolates of A. baumannii harbored bla(OXA-23) gene, from which three isolates were collected from patients and two from hospital environment. Only one isolate harbored bla(NDM-1) gene, which was responsible for carbapenem resistance in A. baumannii. The OprD gene seems to be disturbed by an insertion sequence (IS) in two isolates and affected by polymorphism in one isolate. Pulsed-field gel electrophoresis results showed high genetic diversity among carbapenemase producing A. baumannii. This study highlights the dissemination of bla(OXA-23) and bla(NDM-1) genes in a Libyan setting. Therefore, infection prevention and control practices, antimicrobial stewardship initiatives, and antimicrobial resistance surveillance systems should be implemented to prevent the wide spread of antimicrobial resistance.202134029121
932120.9999Emergence of armA and rmtB genes among VIM, NDM, and IMP metallo-β-lactamase-producing multidrug-resistant Gram-negative pathogens. In the recent years, it has been noted that microorganisms with acquired resistance to almost all available potent antibiotics are increasing worldwide. Hence, the use of antibiotics in every clinical setup has to be organized to avoid irrational use of antibiotics. This study was aimed to establish the pattern of antibiotic sensitivity and relevance of antimicrobial resistance in aerobic Gram-negative bacilli. A total of 103 aerobic Gram-negative bacteria namely Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Citrobacter koserii, Proteus spp., and Pseudomonas aeruginosa were collected from tertiary care centers around Chennai. Kirby-Bauer Disk Diffusion test and study for genes of cephalosporin, carbapenem, and aminoglycoside resistance were done. A descriptive analysis of the data on altogether 103 clinical urine isolates was performed. All strains showed susceptibility to colistin. The frequency of genes encoding 16S rRNA methylases armA and rmtB were 7.8% and 6.8%, respectively. Among metallo-β-lactamases, bla(VIM), bla(IMP), and bla(NDM-1) were detected in 6.8%, 3.8%, and 3.8%, respectively. One E. coli strain harbored bla(SIM-1) gene. Cumulative analysis of data suggested that 30% of the strains carried more than one resistance gene. The current research evidenced the increasing frequency of resistance mechanisms in India. Combined approach of antibiotic restriction, effective surveillance, and good infection control practices are essential to overcome antibiotic resistance.201828870092
933130.9999Molecular characterization and diversity of carbapenemases in Gram-negative bacteria in Libyan hospitals. INTRODUCTION: Antimicrobial resistance has become a major threat to public health, especially in developing countries, due to the uncontrolled consumption of antibiotics. This study aims to characterize antibiotic resistance genes in different bacteria recovered in different healthcare facilities in Libya. METHODOLOGY: 379 samples were recovered from various sources from different sites. 210 samples were able to grow on culture media. 133 Gram-negative carbapenem-resistant strains were recovered from clinical specimens (n = 64), and hospital environments (n = 69). Antibiotic susceptibility tests were performed to select carbapenem-resistant strains. Colistin resistance was tested by the UMIC method to determine the minimum inhibitory concentration. RT-PCR was conducted to detect the incidence of carbapenemases-encoding genes. RESULTS: Gram-negative bacteria showed a low susceptibility to carbapenems. Molecular investigations indicated that NDM-1 was the most prevalent in Enterobacteriaceae isolated from patients and hospital environment (n = 26, n = 41), followed by blaOXA-48 (n = 16, n = 15) and blaVIM (n = 3) from patients and blaKPC (n = 1) from hospital environment. Concerning A. baumannii, blaOXA-23 was detected in strains isolated from patients (n = 8) and hospital environment (n = 6), followed by blaNDM (n = 9) from patients and one from hospital environment. Carbapenem resistance in P. aeruginosa was encoded by modification in OprD encoding gene, such as IS (ISpa26), polymorphism, and a premature stop codon. CONCLUSIONS: Several carbapenem resistant Gram-negative bacteria were identified by the expression of different carbapenemases and the alteration of OprD.202540720466
2122140.9999Phenotypic and genotypic characteristics of carbapenemase- and extended spectrum β-lactamase-producing Klebsiella pneumoniae ozaenae clinical isolates within a hospital in Panama City. Klebsiella pneumoniae spp ozaenae is a versatile bacterial species able to acquire antimicrobial resistance; the species presents a higher antimicrobial resistance profile compared to Klebsiella pneumoniae spp pneumoniae. Carbapenemase and extended spectrum β-lactamase (ESBL)-producing bacteria commonly arise in clinical settings where antimicrobial stewardship is limited. Our study aims to report the phenotypical and genetic characteristics of nosocomial Klebsiella pneumoniae spp ozaenae isolates associated with mortality collected from a tertiary-level hospital in Panama City. In October 2020, 11 consecutive multidrug-resistant Gram-negative isolates were recovered from secretions and blood cultures from hospitalized patients. Nearly 90% (10/11) of these patients died, and bacteria was obtained from six patients for investigation. Biochemical evaluation of the six isolates revealed the presence of multidrug-resistant Klebsiella pneumoniae spp ozaenae. Phenotypic evaluation indicated resistance to carbapenemase and EBSL. In contrast, genetic evaluation by PCR showed that only 30% (2/6) were resistant to CTX-M-1 (CTX-M group 1), whereas 60.7% (4/6) presented carbapenemase resistance genes, and 33.3% (2/6) presented New Delhi metallo-β-lactamase (NDM) resistance genes. Klebsiella pneumoniae ST258 was identified in 83.3% (5/6) of the isolates. Phylogenetic analysis using 16S revealed low homology among the six isolates. These results suggest that antibiotic resistance genes may have been incorporated into these Klebsiella pneumoniae spp ozaenae isolates within the hospital environment. We recommend strengthening the antimicrobial stewardship program and antibiotic control policy, as well as heightened infection control and prevention measures, such as ward sanitation and increased hand washing frequency.202134733509
2115150.9999Assessment of carbapenemase genes and antibiotic resistance profiles in ceftazidime-avibactam resistant Klebsiella pneumoniae isolates: A single-center cross-sectional study. BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is an urgent global health threat due to its rapid spread and limited treatment options. Ceftazidime-avibactam exhibits broad efficacy against gram-negative bacteria, including CRKp; however, emerging resistance to this agent is increasingly reported. Understanding the prevalence of ceftazidime-avibactam resistance and the underlying carbapenemase genes is critical for optimizing antimicrobial stewardship and guiding clinical management. This study aimed to determine the prevalence of ceftazidime avibactam resistance among CRKp isolates collected from various clinical specimens, and to analyze their associated carbapenemase genes and antibiotic resistance profiles. METHODS: This cross-sectional study analyzed 312 K pneumoniae isolates obtained from various clinical specimens of hospitalized patients at a tertiary care hospital in Turkey. Antibiotic susceptibility testing was performed using the disk diffusion method for ceftazidime-avibactam and broth microdilution for both colistin and ceftazidime-avibactam. Molecular detection of carbapenemase genes was carried out using polymerase chain reaction. RESULTS: Ceftazidime-avibactam resistance was identified in 21.5% (67/312) of CRKp isolates. Among these isolates, 37.3% harbored both OXA-48 and NDM genes, 13.4% carried NDM alone, 10.4% carried OXA-48 alone, and 38.8% lacked these genes. The majority of resistant isolates originated from urine (31.3%), followed by tracheal aspirate (29.9%), and blood (22.4%) specimens. The prevalence of colistin susceptibility among ceftazidime-avibactam-resistant CRKp isolates was 56.7%. CONCLUSIONS: The coexistence of NDM and OXA-48 genes is a major contributor to ceftazidime-avibactam resistance in CRKp isolates, particularly in urinary and respiratory tract infections. These findings underscore the need for ongoing surveillance and tailored antibiotic stewardship programs to control the spread of resistance in hospital settings.202541088587
928160.9999Phenotypic and genotypic characterization of carbapenem encoding genes among carbapenem-resistant Gram-negative bacteria isolated from North Casablanca, Morocco. Carbapenem resistance genes in Gram-negative bacteria (CR-GNB) are a major cause of critical infections and are considered an urgent public health concern. The present study aimed to describe the prevalence of CR-GNB and the dissemination of extended-spectrum beta-lactamase (ESBL) and carbapenemase genes in clinical isolates from Casablanca, Morocco. Firstly, the strains were collected and identified using phenotypic and biochemical methods, then the antibiotic susceptibility was evaluated by the disc diffusion assay to screen isolates resistant to carbapenems. Secondly, three traditional methods, the carbapenem inactivation method, the modified Hodge, and the in-house carba-NP, were performed to predict the carbapenemase production by the included strains. Finally, conventional PCR was utilized to validate and detect the carbapenemase- and ESBL-related genes. Concerning the results, out of the identified 122 strains, 48 were CR isolates, including 30 Klebsiella pneumoniae, 13 Escherichia coli, and 5 Pseudomonas aeruginosa. Furthermore, these strains presented a high level of resistance. Moreover, the prediction of carbapenemase production by the phenotypic methods showed variable results. Also, the PCR analysis revealed a high occurrence of β-lactamase (ESBL and carbapenemase) genes in the included clinical strains, and most strains harbored multiple resistance genes. Our findings suggest that the three existing methods have some limitations, and a validation study is still necessary for the carbapenemase diagnostics.202540857960
909170.9998First Description of Colistin and Tigecycline-Resistant Acinetobacter baumannii Producing KPC-3 Carbapenemase in Portugal. Herein, we describe a case report of carbapenem-resistant Acinetobacter baumannii and Klebsiella pneumoniae isolates that were identified from the same patient at a Tertiary University Hospital Centre in Portugal. Antimicrobial susceptibility and the molecular characterization of resistance and virulence determinants were performed. PCR screening identified the presence of the resistance genes bla(KPC-3), bla(TEM-1) and bla(SHV-1) in both isolates. The KPC-3 K. pneumoniae isolate belonged to the ST-14 high risk clone and accumulated an uncommon resistance and virulence profile additional to a horizontal dissemination capacity. In conclusion, the molecular screening led to the first identification of the A. baumannii KPC-3 producer in Portugal with a full antimicrobial resistance profile including tigecycline and colistin.201830404152
1503180.9998OXA-48 Carbapenemase-Encoding Transferable Plasmids of Klebsiella pneumoniae Recovered from Egyptian Patients Suffering from Complicated Urinary Tract Infections. Gram-negative bacteria are common causes of urinary tract infections (UTIs). Such pathogens can acquire genes encoding multiple mechanisms of antimicrobial resistance, including carbapenem resistance. The aim of this study was to detect the carbapenemase-producing ability of some Gram-negative bacterial isolates from urine specimens of patients suffering from complicated UTIs at two vital tertiary care hospitals in Cairo, Egypt; to determine the prevalence of carbapenemase genes among plasmid-bearing isolates; and explore the possibility of horizontal gene transfer to other bacterial species. The collected isolates were subjected to antimicrobial susceptibility testing, phenotypic analysis of carbapenemase production, and molecular detection of plasmid-borne carbapenemase genes, then the extracted plasmids were transformed into competent E. coli DH5α. A total of 256 Gram-negative bacterial clinical isolates were collected, 65 (25.4%) isolates showed carbapenem resistance of which 36 (55.4%) were carbapenemase-producers, and of these 31 (47.7%) harbored plasmids. The extracted plasmids were used as templates for PCR amplification of bla(KPC), bla(NDM), bla(VIM), bla(OXA-48,) and bla(IMP) carbapenemase genes. The bla(OXA-48) gene was detected in 24 (77.4%) of the tested isolates while bla(VIM) gene was detected in 8 (25.8%), both bla(KPC) and bla(NDM) genes were co-present in 1 (3.2%) isolate. Plasmids carrying the bla(OXA-48) gene from 4 K. pneumoniae clinical isolates were successfully transformed into competent E. coli DH5α. The transformants were carbapenemase-producers and acquired resistance to some of the tested antimicrobial agents as compared to untransformed E. coli DH5α. The study concluded that the rate of carbapenem resistance among Gram-negative bacterial uropathogens in Cairo, Egypt is relatively high and can be transferred horizontally to other bacterial host(s).202134571766
2120190.9998Antimicrobial Resistance Patterns of Gram-negative Bacteria in an Iranian Referral Pediatric Hospital: A Present Danger of New Delhi Metallo-β- lactamase. BACKGROUND: Antimicrobial resistance among gram-negative bacteria has been growing, particularly in developing countries, like Iran. The emergence and spread of carbapenem-resistance mechanisms is a major public health concern because no definite treatments have yet been established for this problem. This study aimed to evaluate antibiotic susceptibility of gram-negative bacteria, metallo-β-lactamases (MBLs) and carbapenemase-producing genes, including bla (NDM), bla (VIM), and bla (IMP) in patients referred to Children's Medical Center, Tehran, Iran. MATERIAL AND METHODS: In this cross-sectional study, a total of 944 gram-negative isolates were tested in the study, and antimicrobial susceptibility testing was performed. Moreover, MBL production of carbapenem-resistant isolates, as well as the presence of bla (NDM), bla (VIM), and bla (IMP), was investigated. RESULTS: The most common gram-negative isolated bacteria were Escherichia coli (489 samples, 52%), followed by Klebsiella pneumoniae (167 samples, 18%), Pseudomonas aeruginosa (101 samples, 11%), Enterobacter spp. (64 samples, 7%), Pseudomonas spp. (35 samples, 4%), Acinetobacter baumannii (18 samples, 2%), and Burkholderia cepacia (17 samples, 2%). Imipenemresistant was found in 75%, 61%, and 60% of Stenotrophomonas maltophilia, Enterobacter spp., and A. baumannii isolates, respectively. Moreover, the highest resistance to meropenem was observed in S. maltophilia, A. baumannii, P. aeruginosa, and B. cepacia (100%, 96%, 83%, and 61.5%, respectively). Double disk synergy test (DDST) results showed that 112 out of 255 carbapenem- resistant isolates (44%) were MBL-producing ones. The presence of the bla (NDM) gene was identified in 32 (29%) of MBL-producing isolates, 13 of which were K. pneumoniae, 7 P. aeruginosa, and 7 E. coli, 3 Enterobacter spp., and 2 Klebsiella spp., respectively. The presence of the bla (IMP) and bla (VIM) genes was detected in 2 (2%) and 1 (1%) of MBL-producing isolates. These genes were detected in only MBL-producing P. aeruginosa isolates. CONCLUSION: Our findings suggest the emergence of NDM-producing strains in our hospital, and bla NDM was the most frequently detected carbapenemase gene in MBL-producing P. aeruginosa, K. pneumoniae, and Klebsiella spp. Since such bacteria can easily spread among patients in the hospital, a strong infection control and prevention plan is highly recommended.202337106518